Vigilant IC stops spread norovirus 'stomach flu'

New guideline will stress hand-washing

A wave of the "stomach flu" can be like a tsunami of gastrointestinal illness, affecting patients and health care workers alike. It takes vigilant hand hygiene, cleaning, and use of personal protective equipment to control and prevent hospital outbreaks, says Tara MacCannell, PhD, a health care epidemiologist with the Centers for Disease Control and Prevention's Division of Healthcare Quality Promotion.

"When norovirus is introduced in health care facilities, it tends to blitz through clinical areas," she says. "By the time [hospitals begin] more stringent infection control, it has already affected many of the staff and patients."

A health care-specific CDC guideline on managing a norovirus outbreak is expected later this year to underscore the important infection control measures, says MacCannell.

Even when an outbreak is resolved, it can recur if the virus is still circulating in the community, she says. "Studies show that even if you have exposure to norovirus and recover, re-infection even within a year can occur quite quickly," she says. "It is a community-based disease. It can have a seed in the community and make its way into the health care setting."

It can take as few as 100 viral particles to start an infection, she says. Here are some recommended measures for control of a norovirus outbreak, MacCannell says:

• Ill employees should stay home from work for a minimum of 48 hours after their symptoms resolve. (Local and regional health departments may have their own policies on this issue.)

• Chlorine bleach performs well against norovirus, but the fumes can be an irritant to the eyes, skin, and mucous membranes. The U.S. Occupational Safety and Health Administration (OSHA) has a permissible exposure limit for chlorine of 1 part per million (3 milligrams per cubic meter) as a ceiling limit — or a limit that should not be exceeded at any time. The National Institute for Occupational Safety and Health has a recommended exposure limit of 0.5 ppm (1.45 mg/m3) for a 15-minute sampling period. Neohydrogen peroxide products are also effective, she says.

• Employees who may come into contact with bodily fluids or contaminated surfaces should wear gloves and a gown. If there's a potential for contact with sprays, such as from vomiting patients, employees should also wear procedure masks and eye protection, she says.

• Cohort staff in units that are experiencing an outbreak and exclude non-essential staff, volunteers, and students from that area.

• Hand-washing is preferred to alcohol-based gels because the mechanical action removes the virus, she says. Alcohol-based sanitizers can be an adjunct method of hand hygiene, but MacCannell notes, "Norovirus is an extremely hardy virus and can be considered still infective even after exposures to high concentrations of alcohol."

• Although food-handling is not a common route of transmission in hospitals, it is a source of transmission in the community. Food service workers should never report to work when they are sick. The use of disposable dishes or utensils is not necessary, she says.